You may make small purchases without noticing how they quickly add up (the "latte factor"). You probably notice your larger expenditures. Think back to your latest sizable purchase. Let's say costing $500 or more. What was it?
This podcast accompanies a blog post at Riscario Insider: http://blog.riscario.com/2010/02/how-did-you-make-your-last-500-purchase.html